Corrosion Failures
Theory, Case Studies, and Solutions
Wiley Series in Corrosion Series

Provides corrosion basics in a lucid manner to students and working professionals and over 80 corrosion-failure analysis case studies

• Correlates Failure Analysis with Corrosion Science
• Exclusively provides corrosion-related failure analysis case histories in one place in a convenient format
• One-stop shop for both science and real time occurrence of the phenomenon of corrosion
• Full coverage of all MOC, Materials of Construction, used for process equipments
• Simple but Lucid presentation of Failure Analysis procedure

About the Authors xiii

Foreword xv

Preface xvii

1 Introduction 1

1.1 The Phenomenon of Corrosion 1

1.2 Importance of Corrosion 2

1.2.1 Cost of Corrosion: Direct and Indirect 2

1.3 The Purpose and Format of the Book 6

References 7

2 Thermodynamics and Kinetics of Electrochemical Corrosion 9

2.1 Introduction 9

2.2 Thermodynamics 10

2.2.1 Corrosion Reactions and Gibbs Free Energy Change 10

2.2.2 Electrochemical Nature of Corrosion 11

2.2.3 Summary 16

2.3 Kinetics of Corrosion 17

2.3.1 Description of a Corrosion System 18

2.3.2 Predicting Corrosion 19

2.3.3 Passivity 21

2.3.4 Summary 22

2.4 Corrosion Evaluation and Monitoring 23

2.4.1 Electrochemical Techniques 24

2.4.2 Non-electrochemical Techniques 26

References 27

3 Forms of Corrosion 29

3.1 Introduction 29

3.2 Uniform Corrosion 30

3.3 Galvanic Corrosion 31

3.3.1 Factors Affecting Galvanic Corrosion 31

3.3.2 Controlling Galvanic Corrosion 34

3.4 Pitting Corrosion 35

3.4.1 Pitting Process and Pitting Morphology 35

3.4.2 Factors Affecting Pitting Corrosion 35

3.4.3 Controlling Pitting Corrosion 38

3.5 Differential Aeration-Assisted Corrosion (Crevice Under Deposit and Water-Line Corrosion) 39

3.5.1 Characteristics of Differential Aeration Corrosion 39

3.5.2 Factors Affecting Differential Aeration Corrosion 40

3.5.3 Differential Aeration Corrosion Control 41

3.6 Intergranular Corrosion 41

3.6.1 IGC of Stainless Steels 41

3.6.2 Weld Decay of Stainless Steels 45

3.7 Selective Dissolution/Selective Attack 47

3.7.1 Characteristics of Selective Dissolution 47

3.7.2 Dezincification 47

3.7.3 Graphitic Corrosion 49

3.8 Flow-Assisted/Erosion/Cavitation Corrosion 50

3.8.1 Flow-Assisted Corrosion (FAC) 50

3.8.2 Erosion Corrosion 51

3.8.3 Cavitation Damage 55

3.9 Stress Corrosion Cracking 55

3.9.1 Characteristics of SCC 56

3.9.2 Effect of SCC on Mechanical Properties 57

3.9.3 Factors Affecting SCC 59

3.9.4 Controlling SCC 63

3.10 Hydrogen Damage 63

3.10.1 Low Temperature Hydrogen-Induced Cracking 63

3.10.2 High Temperature Hydrogen Damage/Decarburization 67

3.11 Stray Current Corrosion 68

3.12 High Temperature Corrosion 70

3.12.1 Oxidation 70

3.12.2 Sulfidation 71

3.12.3 Hot Corrosion 71

3.12.4 Chloridation 71

3.12.5 Carburization/Metal Dusting 72

References 72

4 Materials of Construction for Chemical Process Industries 75

4.1 Introduction 75

4.2 Cast Irons 76

4.3 Carbon Steels 78

4.3.1 Corrosion 79

4.3.2 Stress Corrosion Cracking Including Hydrogen Cracking and Sulfide Stress Cracking 80

4.3.3 Caustic Stress Corrosion Cracking 81

4.3.4 Favorable and Unfavorable Points in Using Carbon Steel as MOC 82

4.4 Low Alloy Steels 82

4.5 Stainless Steels 86

4.5.1 Ferritic/Martensitic Stainless Steels 87

4.5.2 Austenitic Stainless Steels 88

4.5.3 Super Austenitic Stainless Steels 92

4.5.4 Duplex Stainless Steels 94

4.6 Nickel Base Alloys 96

4.7 Copper Base Alloys 96

4.8 Titanium 99

4.9 Aluminum Alloys 100

4.10 Nonmetallic Materials 102

4.11 Ceramics/Inorganic Oxide Glasses 103

4.12 Organic Polymers/Plastics 103

4.13 Materials Selection for Corrosion Prevention in Hydrocarbon Service 104

4.13.1 Materials Selection as per NACE MR0175 107

References 109

5 Failure Analysis Procedure with Reference to Corrosion Failures 111

5.1 Introduction 111

5.2 Purpose of Failure Analysis Investigations 112

5.3 Failure Analysis Steps 112

5.3.1 Site Visit 112

5.3.2 Tests on the Samples 114

5.3.3 Analysis Interpretation and Diagnosis of the Failure 116

5.4 Failure Analysis Report: Contents and Preparation 117

References 118

6 Case Studies 119

6.1 Preamble 119

Classification of Case Studies 120

General 123

1 Bromine Preheater in a Pharmaceutical Fine Chemical Plant 124

2 Structurals in a White Clay Manufacturing Plant 125

3 Sea Water Cooler Tubes in an Oil Refinery 126

4 Package Boiler Tube in an Organic Chemical Plant 127

5 Shell of a Packed Column for Ammonia and Water Contact in an Ammonia Processing Plant 128

6 Instrumentation Tube in an Offshore Platform of an Oil and Gas Plant 129

7 Plate Type Heat Exchanger/Cooler in a Sulfuric Acid Plant 130

8 Dissimilar Stainless Steel Weld in an Organic Chemical Plant 131

9 Digestor Preheater in a Pulp and Paper Plant 132

10 Esterification Column in an Organic Chemical Plant 133

11 Half Pipe Limpet Coil of a Stirred Reactor in an Organic Chemical Plant 134

12 Firewater Lines Buried Underground in an Organic Chemical Plant 135

13 Alcohol Superheater in a PVC Manufacturing Petrochemical Plant 136

14 Package Boiler Tubes in an Alcohol Distillery Plant 137

15 Reducers in a Reformer Tube in an Ammonia Plant of a Fertilizer Industry 138

16 Pressure Safety Valve (PSV) Fitting on Instrumentation Tubes in an Off-shore Platform in an Oil and Gas Company 139

17 Water Drum (Mud Drum) Shell in a Coal-Fired Steam Boiler 140

18 Tubes in a Kettle Re-boiler of an Amine Plant 141

19 Evaporator Tubes in an Organic Chemical Plant 142

20 Top Tube Sheet Vent Equalizer Weld Zone of a Gas Cooler in a Petrochemical Plant 143

21 Bottom Row Tubes in a Kettle Re-boiler of an Organic Chemical Plant 144

22 Cages for Filter Bags in an Inorganic Chemical Plant 145

23 High Temperature Generator (HTG) Tubes of Vapor Absorption Chiller of an Air-Conditioning and Refrigeration Unit 146

24 Gasket Seat in a Shell and Tube Condenser in a Petrochemical Plant 147

25 Acid Gas CO2 Cooler Condenser in Ammonia Plant of a Fertilizer Unit 148

26 Naphtha Coolers in a Fertilizer Plant 149

27 U Type Jet Dyeing Machine in a Textile Dyeing Unit 150

28 Acetic Acid Manufacturing Unit in a Petrochemical Plant 151

29 Large Stainless Steel Pipeline in a Urea Plant of a Fertilizer Unit 152

30 Heat Recovery System of a PVC Unit in a Petrochemical Plant 153

31 EDC Furnace Coil of a PVC Plant in a Petrochemical Unit 155

32 Internals of a Stirred Reactor Processing Ortho Phosphoric Acid 157

33 Salt Evaporator 158

34 Cooler/Condenser Tubes of an Absorption Chiller Machine of an Airconditioning Plant 159

35 Nitro Mass Cooler in an Organic Chemical Plant 161

36 Fertilizer Industry Ammonia Plant Natural Gas Feed Preheater Coil 162

37 Petrochemical Unit. PVC Plant. Radiant Coils of the EDC Pyrolysis Furnace 164

38 Exhaust Gas Boiler in a Sugar Mill 166

39 Domestic Storage Water Heater 167

40 Stirred Reactor in a Rubber Chemical Plant 168

41 Stainless Steel Tubes During Long Storage in Packed Condition 169

42 Fertilizer Plant. Ammonia Units. Secondary Waste Heat Boiler Tubes 170

43 Hospital Hydroclave for Treating Wastes 172

44 Petrochemical Plant. Phosgene Absorption Column Internals 174

45 Fertilizer Unit Ammonia Plant Start-Up Preheater Outlet Line 176

46 Petrochemical Plant Underground Fire–Water Pipelines 177

47 Monel Clad Evaporator in a Pure Water Plant 178

48 Loop Steamer Machine in a Textile Dyeing Unit 179

49 Rubber Chemicals Plant: Leakage in Process Pipelines 180

50 Clay Drier in a Clay manufacturing Plant 181

51 Hydrogen Sulfide Processing Plant 182

52 Textile Bleaching Vessel in a Dyeing Industry 184

53 Condenser of an Absorption Chilling Machine in an Air-Conditioning Plant 185

54 Petrochemical Complex: Lube Oil Cooler Tubes of Captive Gas Turbine Power Plant 187

55 Petrochemical Plant: Plate Heat Exchanger (PHE) Exchanging Heat Between Spent Caustic and Vent Gas in a Cracker Plant 188

56 Inorganic Chemical Plant: Distillation Pots 189

57 Starch Industry: Economizer Tubes of High Pressure Captive Boilers 190

58 Rubber Chemical Plant–Crump Slurry Tank 191

59 Petrochemical Plant: Gas Cracker Unit Dilute Steam Kettle Re-boiler 193

60 Textile Dyeing Unit: Jet Dyeing Machine Shell 194

61 Oil Refinery: 12 Inch Dia. Overhead Pipeline 195

62 Fertilizer Plant: CO2 Compressor Inter-stage Cooler 196

63 Oil Refinery: Flash Crude Heater Shell Cover Drain Nozzle 198

64 Oil Refinery: Light Cycle Oil Steam Generator 199

65 Organic Chemical Plant: High Pressure Autoclave in R&D Laboratory 200

66 Fertilizer Industry: Captive Power Plant: Economizer Tube 202

67 Inorganic Chemicals Plant: Reactor Shell 203

68 Reactor for an Organic Chemical Plant 204

69 Fertilizer Unit. Ammonia Plant. Primary Waste Heat Boiler 205

70 Pulp and Paper Plant. TL Vertical Screen Inlet Line of the Paper Section 207

71 Fertilizer Plant. Underground Sections of Cooling Water and Fire Hydrant Water Pipe Lines 208

72 Thermal Power Plant. Condenser Cooling Sea Water In-take Line. Butter Fly Valve 210

73 Petrochemical Plant. Pressure Transmitter Sensors 211

74 Organic Chemicals Plant: Coolers and Condensors 212

75 Organic Chemicals Plant: Alcohol Vaporizer 214

76 Organic Chemicals Plant. Thermowells 215

77 Fertilizer Unit. Ammonia Plant. Gas to Gas Heat Exchanger 216

78 Oil Refinery. Sulfolane Recovery Column Reboiler 217

79 Oil Refinery. Hydrocarbon vapor-liquid heat exchanger 218

80 Chlor-Alkali Plant Stainless Steel Laboratory Reactor 219

Index 221

K. Elayaperumal has close to 50 years of experience in Corrosion and Metallurgical Analysis. Since 1979 he has been a Corrosion & Metallurgical Consultant extending advisory Consultancy Services in the areas of Corrosion Prevention, Materials Selection, Failure Analysis, Water treatment etc. as related to Process Industry. He is the recipient of the National Metallurgist Award instituted by Ministry of Iron and Steel, Government of India, for contribution in Corrosion Prevention and Failure Analysis and also the Life Time Achievement Award from NACE International India Chapter.

V. S. Raja is currently a professor in the Department of Metallurgical Engineering and Materials Science at the Indian Institute of Technology Bombay, Mumbai, India. He has guided about 20 doctoral and 100 master’s students in Corrosion and has been a Consultant to over 50 industries; has over 120 publications in various peer reviewed journals & books and also delivered over 100 plenary, keynote and invited talks in conferences. He is a recipient of Meritorious award by NACE international India Section and Excellence in Teaching award by IIT Bombay and a Fellow of NACE International and Indian Institute of Metals.